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Electrochemical redox processes involved in carbon-coated KVPO4F for high voltage K-ion batteries revealed by XPS analysis

Electrochemical redox processes involved in carbon-coated KVPO4F for high voltage K-ion batteries revealed by XPS analysis

would be related to the high-potential domain. Since KVPF and KVPF-C have close particles size (Fig. S2), the carbon coating was shown – as expected – to promote better transport properties within the positive electrode, lower polarization of the cell, smaller electrolyte degradation at high voltage and thus optimized performances. XPS analysis

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XPS analysis of the PC/PVDF interface modified by PMMA. Location of the PMMA at the interface

XPS analysis of the PC/PVDF interface modified by PMMA. Location of the PMMA at the interface

In conclusion, XPS analysis provides evidence for the coverage of the PC/PVDF interface by PMMA when PVDF is preblended with as small as 10 wt% of PMMA. However, the complete removal of PC before the XPS analysis of the PVDF surface leads to the collapse on this surface of the PMMA chains that were originally part of a PC/PMMA diffuse region and contributed to the physical properties of the actual PC/PVDF interface, i.e. interfacial tension and interfacial adhesion. It is thus not surprising that the PC/PVDF interface appears to be saturated by PMMA when only 10 wt% of PMMA is preblended with PVDF and the surface composition of the PVDF phase is analyzed by XPS, although measurement of the macroscopic properties of the real interface indicates that ca. 35 wt% of PMMA is required.
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New insight on early oxidation stages of austenitic stainless steel from in situ XPS analysis on single-crystalline Fe–18Cr–13Ni

New insight on early oxidation stages of austenitic stainless steel from in situ XPS analysis on single-crystalline Fe–18Cr–13Ni

the increasing saturation level measured at 150 ◦ C and 250 ◦ C in the present work. Thus, it is shown by in situ XPS analysis of the initial stages of the Fe-18Cr-13Ni surface oxidation that there is no apparent effects of oxygen pressure on the oxidation kinetics in the tested pressure range (< 10 −6 mbar) and that the effects of temperature are different depending on oxygen exposure. The exposure of about 10 L can be estimated as the threshold below which the oxidation rate would be essentially limited by the sticking coefficient suggesting a nucleation phase reaching saturation at this exposure. Beyond 10 L, atomic displacement and/or transport would become rate limiting suggesting that the oxidation process has entered the growth phase leading to the increase of the surface oxide formation with increasing temperature.
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Chemical Interactions at the Al/Poly-Epoxy Interface Rationalized by DFT Calculations and a Comparative XPS Analysis

Chemical Interactions at the Al/Poly-Epoxy Interface Rationalized by DFT Calculations and a Comparative XPS Analysis

In this work, we analyze experimentally a buried interface of Al/poly epoxy through ex situ XPS under ultrahigh vacuum (UHV) and atomic force microscopy (AFM) under ambient conditions. Interaction of one Al atom with representative epoxy models is then rendered to identify adsorption sites. We propose a simulated atom by atom deposition on the considered epoxy model systems, constraining to a few adsorbed atoms as we are limited by the size of the model systems. The present study elaborates on metallization energetics to understand experimental XPS results on the buried Al/poly epoxy interface. Further, the charge transfer at the model interface is elucidated. A suitable molecular model is determined through a comparative experimental/theoretical XPS analysis, which is then helpful in revealing interactions at the Al/poly epoxy interface. The discussion section attempts to address some open questions risen in previous works 18 , 20 and to illustrate the electronic structure of model epoxy validated by experimental XPS.
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XPS analysis of PE and EVA samples irradiated at different γ-doses

XPS analysis of PE and EVA samples irradiated at different γ-doses

Polyethylene-vinyl acetate XPS a b s t r a c t The principal plastic materials used for the fluid contact and storage in the biopharmaceutical industry are mainly made up of semi-crystalline polymers, polyolefins, PVC, Siloxane and PET. The polyethylene (PE) and the polypropylene (PP) are often used as fluid contact in multi-layer materials like films. As one sterilisation way of single-use plastic devices used in medical and pharmaceutical fields can take place via ␥-irradiation, the effect of sterilization on plastics must be investigated. The irradiation process leads to the production of radicals, which can generate changes in the polymer structure and on the polymer surface. It is well known that the presence of oxygen with free radicals precede the generation of peroxide species so called ROS (reactive oxygen species) which are highly reactive. The purpose of this work is to investigate the ␥-rays impact on the surface of PE (polyethylene) and EVA (polyethy- lene vinyl alcohol) based films when ionized at different doses. X-ray Photoelectron Spectroscopy (XPS) was applied to determine the surface compositions of the polymers to highlight the different chemical moieties generated during the ␥-irradiation process and to monitor the potential presence of the ROS.
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Depth-profiling X-ray photoelectron spectroscopy (XPS) analysis of interlayer diffusion in polyelectrolyte multilayers

Depth-profiling X-ray photoelectron spectroscopy (XPS) analysis of interlayer diffusion in polyelectrolyte multilayers

ray exposure time while still obtaining an acceptable resolution and signal-to-noise ratio at each point in the depth profile. Diffusion of Chitosan in Hydrogen-Bonded Multilayers. To explore the question of whether the adsorbed chitosan diffuses into the swollen hydrogen-bonded region and by how much, the nitrogen signal from the amine on chitosan was analyzed as a function of depth for hydrogen-bonded multilayers exposed to a 0.1% (wt/vol) CHI solution at pH 3 for a specified amount of time. The chitosan solution acted as an infinite supply for diffusion of chitosan into the hydrogen-bonded region. All samples were rinsed with water for 4 min and dried with nitrogen gas before analysis. The compiled spectra for chitosan exposure times of 1, 3, 10, and 60 min (CHI1, CHI3, CHI10, and CHI60) are plotted in Fig. 2 A–D. Color was added to highlight the approximate locations of the distinct regions of the PEM film, using the same color scheme shown in Fig. 1A. The depth of the (red) chitosan region was determined by ana- lyzing the intensity of the N1s signal with depth. When the N1s signal dropped to background levels, the spectrum was colored yellow to denote the hydrogen-bonded region. Finally, the (black) adhesion layer starts when the N1s signal increases at the base of the film as a result of the presence of nitrogen-containing PDAC. The spectra from Fig. 2 A–D were analyzed to determine the atomic percentage of nitrogen with depth, as seen in Fig. 2E. A film not exposed to chitosan is shown in Fig. S2 . The concentration of nitrogen in the multilayer film increased systematically with time of exposure to the chitosan solution. Also, the maximum depth at which an appreciable nitrogen signal was observed increased with time. Separate experiments showed that the PDAC from the ad- hesion layers does not enter the hydrogen-bonded region during the assembly process, even after many hours at pH 3 ( Fig. S2 ). Thus, the only source of nitrogen in the film, above the 80-nm
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Depth-profiling X-ray photoelectron spectroscopy (XPS) analysis of interlayer diffusion in polyelectrolyte multilayers

Depth-profiling X-ray photoelectron spectroscopy (XPS) analysis of interlayer diffusion in polyelectrolyte multilayers

In the absence of a blocking layer, chitosan from the (HA3/ CHI3) multilayer film diffuses into the entire hydrogen-bonded film during fabrication, producing a high nitrogen signal through- out, as seen in Fig. 4B. Although the film has fewer total layers deposited than the multilayer films with blocking layers, the in- terlayer diffusion of chitosan allows for a large increase in the final film thickness, as shown by the leftmost data point in Fig. 4B. This large increase in thickness is characteristic of exponential growth, which is caused by the diffusion of polymers and polymer pairs in and out of the film during deposition (20). As a result, we expect chitosan, not only from the first bilayer deposition but also from the subsequent depositions, to be present throughout the film. Similar chitosan diffusion into the hydrogen-bonded region also is observed when the order of polymer deposition is switched from HA first (HA3/CHI3) to chitosan first (CHI3/HA3), as revealed in Fig. S7 . As a result of macromolecules such as chitosan diffusing through- out a film, hydrogen-bonded films might be used as scaffolds for easy loading of drugs or other macromolecules of interest (3, 55). An interesting question concerning the use of depth-profiling XPS with C 60 + sputtering is: What level of vertical resolution is
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Sorption of Eu(III) on Attapulgite Studied by Batch, XPS and EXAFS Techniques.

Sorption of Eu(III) on Attapulgite Studied by Batch, XPS and EXAFS Techniques.

complexes, (≡X) 2 Eu + and (≡S w O) 2 Eu(OH) 2 – (15). XPS analysis. The XPS analysis shows that the bonding energy (B.E.) of Eu 3d 5/2 increases from 1134.94 eV on attapulgite to 1135.01 eV on HA-attapulgite hybrids. The main peak of Eu 3d 5/2 changes about 0.07 eV, which indicates that HA has changed the mechanism or species of Eu(III) sorption on attapulgite. The Eu 3d 5/2 core level region spectrum is fitted by deconvolution. In binary Eu/attapulgite system, two peaks at 1133.89 and 1135.60 eV are achieved; however, three peaks at 1134.41eV, 1134.89 and 1136.34eV are used to fit the Eu 3d 5/2 spectrum well in ternary Eu/HA/attapulgite system ( Figure SI-11 ). According to the surface complexation model results, the peaks in the range of 1133.41 eV and 1134.89 eV may be assigned to the species of ≡S w OHEu 3+ and ≡X 3 Eu 0 , respectively. The peak at 1136.34 eV corresponds to O=C-O-Eu-O-, which is due to the functional groups of
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XPS study of Ni-base alloys oxide films formed in primary conditions of pressurized water reactor

XPS study of Ni-base alloys oxide films formed in primary conditions of pressurized water reactor

evidenced in figure 3, a minimum of 3 peaks is needed to fit the resolved envelope shape. The comparisons of (i) the BE values, (ii) the shape of the envelopes, as well as (iii) the area ratios between the 3 peaks seen in figures 3 (a) and (b) for Cr 2 O 3 and NiCr 2 O 4 respectively, leads to the conclusion that I peak1 /I peak2 is the unique fitting parameters of Cr-2p 3/2 that allow a separation of these two oxides by XPS analysis, with the energy resolution achieved in this work. However, in the case of a mixture of these compounds, and particularly for samples corroded in PWR primary media (for which carbon contamination and/or water adsorption are expected to be higher than in the case of reference compounds), it can be difficult to achieve a clear separation of these two oxides.
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Study of the surface oxides and corrosion behaviour of an equiatomic CoCrFeMnNi high entropy alloy by XPS and ToF-SIMS

Study of the surface oxides and corrosion behaviour of an equiatomic CoCrFeMnNi high entropy alloy by XPS and ToF-SIMS

7 Table 2 The parameters for fitting the XPS 3p spectra of the pure metals and oxides Firstly, the standard 3p core level peaks for the pure metals were recorded using pure metals from batches used to manufacture the CoCrFeMnNi HEA. These pure metal samples were polished with 2400 grit SiC paper, and then introduced into the XPS analysis chamber. Samples were sputtered using an Ar + ion beam to remove surface oxides and contaminants and obtain metallic surfaces. High resolution XPS 3p core level spectra were recorded and curve fitted using the Thermo Electron software Avantage with an iterative Shirley-type background subtraction. All the parameters, including binding energy (BE), full width at half maximum (FWHM), Gaussian-Lorentzian(GL) ratio and asymmetry factor, were automatically adjusted by the software to best fit the peaks of pure metals. An asymmetric function was necessary for the peak fitting of metal peaks, as expected for transition metals (owing to the conduction electron scattering amplitude for inter-band absorption or emission in metals, at the Fermi level[47, 48]). The detailed parameters for fitting the 3p peaks of pure metals are shown in Table 2. For Ni 3p, a splitting of the metallic component is observed (spin orbit coupling is due to the coupling between the electron spin momentum and its orbital angular momentum). Generally, this effect is visible for p, d and f core levels but spectral resolution can limit this splitting. It is the case here for the 3p orbitals of Cr, Mn, Fe and Co.
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DFT Simulation of XPS Reveals Cu/Epoxy Polymer Interfacial Bonding

DFT Simulation of XPS Reveals Cu/Epoxy Polymer Interfacial Bonding

largely superior to the proportion of interface Cu; hence, it is not possible to distinguish Cu −O contributions. 3.3. Cu −Polymer Surface Interactions as Evidenced from the Combined Theoretical and Experimental XPS Analysis. The 2a configuration corresponds to the strongest adsorption site for Cu. However, geometries 1, 2a, and 2b have been tested for further simulation of the XPS spectrum of the metalized surface to correlate with the experimental counter part. Case 1 calculations with a partial occupancy of the C 1s molecular orbitals do not converge or converge with unrealistic binding energy shifts, indicating either a numerical issue or an unstable con figuration. Therefore, in the following, we present the results for cases 2a and 2b. Table 3 shows the chemical shifts calculated with the uGTS method in these two cases.
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An Auger and XPS survey of cerium active corrosion protection for AA2024-T3 aluminum alloy

An Auger and XPS survey of cerium active corrosion protection for AA2024-T3 aluminum alloy

XPS analysis for the coated panels has shown well-identified chemical entities from the coating but also from the AA2024 substrate. For instance, after 300 s of immersion in the conver- sion bath, the large scale survey ( Fig. 2 A) of AA 2024-T3/Ce CC (e.g., [Ce] = 0.1 M) system displays emergence of the main differ- ent orbitals (Al2p, Al2s, C1s, O1 s and Ce3d) with intense signals ( Table 1 ). The coating, very few microns thick, appears to be quite homogeneous and leveling ( Fig. 2 B) but the observation of some substrate elements with the XPS technique would attest of a cer- tain porosity of the deposit. After 1 s of immersion, The XPS data give, at the substrate surface, a Ce/Al ratio between 0.4 and 0.5 for [Ce] = 0.1 M when it is 6 times higher for the [Ce] = 0.5 M in rela- tion with a real difference of deposit thickness. For longer times of immersion (e.g. 300s), the Ce/Al ratio is quite stable for 0.1 M whereas it drastically drops for 0.5 M. This could confirm the dam- aging increase of the coating at high cerium concentration with the immersion time.
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An Auger and XPS survey of cerium active corrosion protection for AA2024-T3 aluminum alloy

An Auger and XPS survey of cerium active corrosion protection for AA2024-T3 aluminum alloy

XPS analysis for the coated panels has shown well-identified chemical entities from the coating but also from the AA2024 substrate. For instance, after 300 s of immersion in the conver- sion bath, the large scale survey ( Fig. 2 A) of AA 2024-T3/Ce CC (e.g., [Ce] = 0.1 M) system displays emergence of the main differ- ent orbitals (Al2p, Al2s, C1s, O1 s and Ce3d) with intense signals ( Table 1 ). The coating, very few microns thick, appears to be quite homogeneous and leveling ( Fig. 2 B) but the observation of some substrate elements with the XPS technique would attest of a cer- tain porosity of the deposit. After 1 s of immersion, The XPS data give, at the substrate surface, a Ce/Al ratio between 0.4 and 0.5 for [Ce] = 0.1 M when it is 6 times higher for the [Ce] = 0.5 M in rela- tion with a real difference of deposit thickness. For longer times of immersion (e.g. 300s), the Ce/Al ratio is quite stable for 0.1 M whereas it drastically drops for 0.5 M. This could confirm the dam- aging increase of the coating at high cerium concentration with the immersion time.
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Unravelling local environments in mixed TiO2–SiO2 thin films by XPS and ab initio calculations

Unravelling local environments in mixed TiO2–SiO2 thin films by XPS and ab initio calculations

As can be seen in Fig. 1 , the DFT results are in a good qualitative agreement with the normalized experimental spectra. Although the qualitative agreement is excellent, a more quantitative test is needed to verify the aforementioned assumptions. With the information from analysis of coordination numbers and first neighbours we can easily sort the binding energies into components corresponding to the various atomic environments. The amorphous structure, represented by our model at least to the degree possible by the limited supercell size, contains a variety of local environments. An oxygen atom can have two, three or four neighbours with different number of Ti or Si atoms – see
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Photovaporisation prostatique par laser Greenlight® XPS 180 W versus résection prostatique : résultats fonctionnels prospectifs à 6 mois

Photovaporisation prostatique par laser Greenlight® XPS 180 W versus résection prostatique : résultats fonctionnels prospectifs à 6 mois

Trois chirurgiens étaient considérés comme junior, avec moins de quatre années d’expérience en post-internat. Deux chirurgiens n’ont fait que des RTUP. Seul un chirurgien était considéré comme expert (6) avec plus de 150 procédures. Les PVP étaient réalisées selon la technique de Malek et al (7) décrite en 1998. Le matériel utilisé était un porte fibre Storz ch 26 (figure 1), ou un cystoscope Storz ch 23, un générateur Greenlight® XPS™ 180 W, une fibre laser MoXy™. Dans un premier temps le col vésical et le lobe médian étaient vaporisés à une puissance de 80 W, puis la puissance pouvait être augmentée jusqu’à 180 W sur les lobes latéraux en fonction du volume prostatique et du choix de l’opérateur. La puissance était limitée à 80 W dans la région latéromontanale pour éviter les lésions sphinctériennes. Aucune échographie endorectale de contrôle per-opératoire n’a été réalisée. Pendant et après l’intervention, le liquide d’irrigation était du sérum physiologique.
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The native oxide film on a model aluminium-copper alloy studied by XPS and ToF-SIMS

The native oxide film on a model aluminium-copper alloy studied by XPS and ToF-SIMS

XPS spectra recorded on AlCu2.2at% sample are shown in Figure 5. The main elements on the surface (Figure 5a) are aluminium, carbon, oxygen and copper (weak signal). The Al2p core level spectrum (Figure 5b) is not used to characterize the surface due to an overlap between Al2p and Cu3p[42]. The Al2s core level region (Figure 5c) is decomposed into three peaks at binding energies of 118.2eV (metallic aluminium) and 121.0eV (aluminium oxi/hydroxide) and a peak corresponding to Cu3s photoelectrons (at an energy of 123.2eV[43]). The C1s core level spectrum (Figure 5f) presents four components: at 286.7eV (C-C bonds), 288.3 eV ( C-O bonds), 290.5 eV (O-C=O bonds) and 291.8 eV ( presence of carbonate 𝐶𝑂 3 2− ) .This decomposition is currently used to describe the contamination layer[44–46]. The O1s core level presents a large peak (Figure 5g). It is decomposed into two peaks at 533.0eV and 534.0eV corresponding to oxygen O 2- and the presence of a hydroxylated component on the surface
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Analyse par XPS d'empilements High-K Metal Gate de transistors CMOS et corrélation des décalages d'énergie de liaison aux tensions de seuil

Analyse par XPS d'empilements High-K Metal Gate de transistors CMOS et corrélation des décalages d'énergie de liaison aux tensions de seuil

121 IV/ Conclusion du chapitre On a vu dans cette partie que, en utilisant le spectromètre dit industriel, soit le Revera Veraflex II, nous sommes capables de mesurer de faibles variations d’énergie de liaison de façon reproductible et répétable. Cela est dû au fait que l’on dispose pour cette étude d’outils de mesures et de procédés fiables et stables dans le temps. Ces mesures ne sont de plus pas sensibles au charging XPS, grâce au fait que tous nos dépôts sont effectués sur des plaques de 300mm de diamètre. Les charges induits par XPS sont donc en théorie évacués par une électrode de grande surface. Afin de se placer dans des conditions d’analyses optimales, les mesures XPS sont effectuées immédiatement après l’étape de procédé (dépôt ou recuit), et ce pour toutes les expériences réalisées durant cette étude. De plus, la comparaison des résultats obtenus par la méthode COCOS avec les résultats XPS semblent montrer que les décalages en énergie de liaison sont principalement corrélés à des apparitions de charges. Il est donc nécessaire d’intégrer la mesure COCOS dans notre protocole expérimental de mesure.
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Surface Analysis of Isolated Nanoobjects by XPS

Surface Analysis of Isolated Nanoobjects by XPS

NANO 2016, Québec, Canada Surface Analysis of Isolated Nanoobjects by XPS O. Sublemontier 1* , S. Benkoula 2 , D. Aureau 3 , C. Nicolas 2 , M. Patanen 2 , H. Kintz 1 , X. Liu 2 , M.A. Gaveau 1 , J.L. Le Garrec 4 , E. Robert 2 , F.A. Barreda 1,2 , A. Etcheberry 3 , C. Reynaud 1 , J.B.

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Unravelling molecular interactions in uracil clusters by XPS measurements assisted by ab initio and tight-binding simulations

Unravelling molecular interactions in uracil clusters by XPS measurements assisted by ab initio and tight-binding simulations

Discussion To understand how the different interactions in the cluster affect the observed shift a simplified bottom-up theoretical approach has been developed. This approach is motivated by the un-sustainable computational cost of the calculation of XPS lines in large (>10 molecules) clusters, performed on several configurations sampled along equilibrated molecular dynamics trajectories. A posteriori we will demonstrate that such approach well reproduces all the short-range structural motifs and intermolecular patterns of realistic clusters. In detail, several different cluster sizes (from dimer to dodecamer) have been cut out from the uracil crystal structure 8 , 9 in order
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Aversion Analysis

Aversion Analysis

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